Machine or tool for sharpening saws.



H. R. ROBERTS.

MACHINE 0R TOOL FOR SHARPENING SAWS.

' APPLICATION FILED JAILB, 1913.

1 ,O74A64, v Patented Sept. 30, 1913. I

HENRY ROBERT ROBERTS, or BLOOIVISBUR-Y, LONDON, ENGLAND.

. MACHINE OR TOOL FOR SHARPENING SAVI'S.

Specification of Letters Patent.

Patented Sept. 30, 1913.

Application filed January 6, 1913. Serial No. 740,395.

T 0 all whom it may concern Be it known that I, HENRY ROBERT llonnnrs, a subject of the King of Great Britain, residing at 8 Gilbert street, Bloomsbury, London, England, have invented new and useful Improvements in Machines or Tools for Sharpening Saws, of which the following is a specification.

My invention relates to the saw sharpen ing machines or tools of the kind forming the subject of British Letters Patent granted to me No. 3018 ll. In the machine described in the specification of the said British patent the saddle which was placed upon the saw to determine the position of the machine with relation thereto, was adapted, when first placed upon the saw, to bear upon the latter at one end only and to be gradually rocked for the purpose of feeding the beveled grinding disk into the teeth as the grinding proceeded.

According to my present invention I ar range the saddle so that when applied to the saw it rests at both ends upon the latter, the grinding disk being adapted to slide in relation to the frame and being arranged in conjunction with a spring in such a manner that the grinding disk will be gradually pressed down into the teeth as the grinding proceeds. Furthermore, in the former specification the handle for operating the grinding disk was arranged to be rotated in a plane parallel with the plane of the disk. In practice this has been found inconvenient, and according to my present invention I arrange the handle to move in a plane at right-angles to the plane of the disk.

In the accompanying drawing :-Figure l is a side elevation of the machine or tool constructed in accordance with my invention and shown applied to the edge of a saw. Fig. 2 is an end view of the same. Fig. 3 is a section on the line 33, Fig. 1. Fig. 4 is a sect-ion on the line M, Fig. 2, and Fig. 5 is a section on the line 5-5, Fig. 4.

0; indicates the V-shaped saddle which rides-upon the edge of the saw A and which is provided with a bracket 6 to which the main framing c of the tool is connected by the bolt (Z, having a thumb nut so as to permit of the angle of the saddle with relation to the grinding disk being adjusted accord ing to requirements.

6 is the grinding disk which is mounted on a spindle f carried in bearings in a slotted plate 9' sliding on the frame a. This slotted plate is guided, and held in position by T- pieces it, it which have portions extending into the slot of the plate g, the said T-pieces being secured by a screw e and bolt (Z to the frame a, as clearly shown in Figs. 4 and 5. The upper part of this plate extends into a socket or recess j in the frame 0, in which socket or recess a spring 7c is inserted, which spring, by pressing upon the plate 9 serves to press it downward toward the saddle. W' hen the saddle is applied to the edge of the saw the grinding disk 0 is pushed backward against the pressure of the spring I; and as the grinding proceeds the said spring feeds the grinding disk downward to the limit of its movement. The depth to which the disk grinds will be regulated by adjusting the position of the saddle with relation to the grinding disk.

The spindle f carrying the grinding disk has mountedupon it a bevel-pinion Z with which a bevel-Wheel m engages, the said wheel receiving its motion from the main driving spindle a through the medium of the spur-wheel 0 and spur-pinion p, rotating in a plane parallel with the saw.

9 is the driving handle and r the handle for holding the tool during the grinding operation.

Claims:

1. A saw sharpening machine comprising a saddle adapted to rest upon the edge of the saw, a frame pivotally connected to said saddle, means for locking said frame in different relations to said saddle, sliding bearings mounted in said frame, a spindle in said bearings, a grinding disk mounted upon said spindle, means for revolving said spin-' dle, and automatic means for depressing said bearings whereby the grinding disk is fed downwardly.

2. A saw sharpening machine comprising a saddle, a frame pivotally mounted upon said saddle, means for adjusting said frame relatively to said saddle, sliding bearings mounted in said frame, a spindle mounted to revolve in said bearings, a grinding disk rigidly mounted upon said spindle, a pinion also mounted upon said spindle, a gear meshing with said pinion, means for rotating said gear positioned at right angles to said grinding disk, and means for automati-r cally depressing said bearings whereby said grinding disk is fed downwardly. V

HENRY ROBERT ROBERTS. \Vitnesses: 1 7

JOHN E. Bonsrrnm), C. G. REDFERN,

Copies of this patent may be obtained for five cents each, hy addressing the Commissioner of Patents,

Washington, I). G. r 

